A connector used for gasoline fuel piping in automobiles through which a pipe body and a resin tube, a female member, are connected, comprises: a tube connection component upstream along the axis; a cylindrical connector housing having a retainer holding component provided downstream along the axis thereof; and a retainer which is housed or held by a retainer holding component. The resin tube and pipe body are connected together, for example, by fitting the resin tube to the tube connection component and by inserting the pipe body to the connector housing from a downstream opening of the connector housing or retainer holding component to cause a snap-on fitting therebetween. The pipe body to be connected to the connector has an insertion end having an annular protruding flange on the outer circumferential plane. The insertion end is snapped onto the connector or connector housing by inserting the insertion end into the connector housing to cause the annular protruding flange to be snapped onto the pipe body engagement portion. An annular sealing member is provided on the inner circumferential plane of the connector housing to seal the space between the insertion end and the connector housing.
The pipe engagement portion may be, for example, an engagement slit circumferentially extending upstream along the axis of an annular or C-shaped retainer in cross-section along the axis. However, if the engagement slit is not handled with full care during connection, the insertion end of the pipe body may not be inserted completely into the retainer or connector housing, that is, the annular protruding flange may not be engaged with the engagement portion of the pipe body, for example, an engagement slit. As a result, a half-fitting condition may occur. The use of the connection configuration in which a connector and a pipe body are half-fitted usually causes fluid leakage because a sealing member does not seal the space between the connector and the pipe body sufficiently.
It is known to use a removable checker to check whether a pipe body is fitted into the quick connector sufficiently well. A removable checker for checking the connection comprises, for example: a checker body having a pulling component configured in parallel or substantially in parallel with the outer circumferential plane of a connector housing; and an engagement component formed integrally with the checker body or with both ends or both end portions of the checker body. Snapping of the engagement component into an engagement window formed on the connector housing causes the engagement component to be attached to one radial end of the connector housing in the locked state in which the engagement component cannot be pulled away. This is illustrated in Unexamined Japanese Patent Application Publication No. 2003-254484. The removable checker of this type is configured in such a manner that the normal fitting of a pipe body to the connector and the snap-on engagement between the annular protruding flange at the insertion end and a retainer cause the engagement component to be pushed aside by an annular protruding flange, which deforms or moves for example, in an outward radial direction, thereby allowing the removable checker to be pulled off. In this way, whether the connector and pipe body are connected normally or not can be confirmed by pulling the checker upon completion of connection operation. If the checker does not come away from the connector housing even when it is pulled, it is most likely that the pipe body is incompletely fitted thereinto; therefore, the connection procedure should be repeated such that the insertion end of the pipe body will be fully inserted into the connector.
A connector and a pipe body once connected may be disassembled and reconnected to permit, for example, maintenance service. In the connection checking configuration that utilizes a removable checker which is to be removed from the connector housing and withdrawn when the pipe body is connected normally, the connection of the pipe body cannot be confirmed when it is connected a second time. To overcome this problem, another connection checking configuration introducing a connection checking component with one end of the connection checking component connected to a connector housing by using a hinge; and with the other end of the connection checking component connected by a pin. If the pipe body is connected normally to a connector or connector housing is then determined by operating this connection checking component as described in Unexamined Japanese Patent Application Publication No. 2002-213673. When the pipe body is connected normally, the pin on the one end of the connection checking component can be engaged with a slot formed on the connector housing by rotating the connection checking component about this one end. The engagement of the pin with the slot allows the connection checking component to be held in parallel with the connector housing. Nevertheless, if the pipe body is not fully inserted into the connector housing, the pin on the connection checking component will not fit into the slot because the pin interferes with the annular protruding flange formed on the insertion end of the pipe body. Therefore, the insertion-connection status of the connector on the pipe body or connector housing can be determined by checking the engagement state between the connection checking configuration and connector housing. In this connection checking configuration, the pipe body can be pulled away relative to the connector by releasing the engagement between the pin and slot. In addition, the connection status of the pipe body can be checked when the pipe body is connected a second time by operating the connection checking component to cause the pin to be engaged with the slot even though the pipe body is connected a second time after it is pulled out.
Nonetheless, in the connection checking configuration utilizing a connection checking component connected to the connector housing with a hinge, an omission prevention measure cannot be implemented if the measure involves counting the checkers that are removed and the resulting count is used to confirm that connection operations are accurately provided at all required points.